Rivet Assembly Lab Report

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Problem Description The problem presented in this lab is to analyse the von Mises stresses and contact pressures present in an assembly when subjected to set conditions. The assembly consists of two identical plates fastened together by a rivet. One plate is fixed in the x-direction whereas a stretch displacement of 2.5mm in the x-direction is applied to a predetermined face on the opposite plate. The assembly interactions and boundary conditions cause an accumulation of pressure at the curved contact surfaces which will be analysed using finite element analysis methods. Analysis approach In order to obtain accurate finite element results there are a number of features which must be considered to determine the correct analysis approach…show more content…
Each plate applies pressure on the contact surface in opposing directions parallel to the x-axis originally. The bending of the plates causes the rivet to rotate around the z-axis which results in a high contact pressure of 7733 N/〖mm〗^2 accumulating at the edges of the surface. Fig.2 Contact Pressure Plot for Rivet Fig.3 represents the contact pressures experienced by the plate. Each plate experiences almost identical forces at the forces since the material and applied forces are the same in each case. The pressure experienced along the face is not even due to the rotation of the rivet around the z-axis. A maximum pressure of 6607N/〖mm〗^2 is experienced at the surface of the plate. Note how this is much lower than that experienced by the…show more content…
Von Mises stresses by definition is used to predict the yielding of materials under any loading condition from results of a uniaxial tensile test. Von Mises stress is therefore dependent of the Young’s modulus (ratio of stress to strain) of any material. Given that the Young’s modulus for the rivet was defined as 112000Pa, compared to the plates which were 71700Pa, this explains the results obtained. A maximum Von Mises stress value of 5093Pa for the rivet indicates a much lower level of deformation present in comparison to 6728Pa for the